Thursday, 20 April 2017

Solar panels release high levels of greenhouse gas

Solar
Panels Increased Emissions Of A Gas 17,200 Times More Potent Than CO2

New
federal data shows a potent greenhouse gas — that’s also a
byproduct of solar panel construction — is on the rise.

Nitrogen
trifluoride (NF3) is a key chemical agent used to manufacture
photovoltaic cells for solar panels, suggesting government subsidies
and tax credits for solar panels may be a driving factor behind the
1,057 percent in NF3 over the last 25 years. In comparison, U.S.
carbon dioxide emissions only rose by about 5 percent during the same
time period.

NF3
emissions have rapidly increased in Asia as well due to its rapidly
growing solar panel market, and researchers think that many nations
are under-reporting their NF3 emissions by roughly a factor of 4.5.

“By
itself, NF3 is not going to create a climate problem,” Dr. Michael
Prather, an earth science professor at the University of California,
Irvine who tracks NF3 emissions, told
Seeker.
“But everything adds up. Everybody should be paying attention to
the pieces that all add up.”

Solar
panels aren’t the only source of NF3, which is also used to
produce semiconductors and LCD flat screens.

The
1,057 percent increase in US annual emissions of NF3 from 1990 to
2015 compares to an increase of 5.6 percent in carbon dioxide
emissions, according to EPA data in a recently-published draft of a
new report

Other
research,
which did not consider NF3, looked at 40 years of CO2 emissions from
solar panels, including those caused by their production,
then subtracted that by the amount of CO2 they prevented from
being emitted. They found many older solar panels would take a
decade to lead to a net emissions reduction, which can be longer than
their lifespan. They also concluded that the current generations of
panels will probably only just reduce net emissions over years.

The
study concluded that
the solar industry has been “a temporary net emitter of greenhouse
gas emissions” and more modern solar panels have a smaller adverse
environmental impact than older models. Scientists estimated that by
2018 at the latest, the solar industry as a whole will have a
net positive environmental impact.

America’s
CO2 emissions have fallen by more than 12 percent since their high in
2005. U.S. CO2 emissions likely declined
by 2.6 percent in 2015 and
are expected to fall an additional 1.7 percent this year.